Solar barometric distillation for seawater desalting part I: Basic layout and operational/technical features

The report presents an innovative solar barometric distillation technology for seawater desalting (SW-SBD) which has several attractive features such as: (1) efficient vacuum solar collectors of simple construction; (2) a barometric layout for quasi-steady operation at subatmospheric pressure; (3) a demister system of simple mechanical construction; and (4) an electronic control system regulating plant productivity parameters on available solar radiation flux. The proposed seawater desalting technology consists of single-effect distillation with water vapor produced and heated at subatmospheric pressure in a solar collector loop; the basic layout, operational features, and energy efficiency are presented and analysed in detail. Subsequent reports will provide technico-economical data from prototype desalting plants in view of industrial implementation. A promising specific electric energy consumption,∼2 kWm³ offresh water produced, was found by estimating pumping power requirements of major SW-SBD plant pumps. A sizable reduction in produced water cost with respect to an existing solar seawater desalting plant in Abu Dhabi is expected on the basis of a preliminary economic evaluation for a ∼100 m³/d plant prototype.     

Seawater Ozonation of Bacillus subtilis Spores: Implications for the Use of Ozone in Ballast Water Treatment

The potential of ozone for disinfection of ships’ ballast water was investigated using Bacillus subtilis spores as an indicator. The effects of pH, presence of iron, and bacterial strain on disinfection efficacy in seawater, under simulated ballast conditions, were investigated. Ozone dosages of 9 mg/L (pH 7) and 14 mg/L (pH 8.2) and 24 h contact achieved a 4-log inactivation with the various oxidant residuals formed. Iron surface at a ratio to water of 9 m²/m³ impaired the oxidant residuals and the disinfection of spores. Different strains of B. subtilis resulted in different CT values. Ozone does not seem to be a good choice for the control of spore-forming organisms in ballast water, but may be suitable for the control of other species.     

Theoretical analysis of a multiple-effect diffusion still producing highly concentrated seawater

A multiple-effect diffusion still producing highly concentrated seawater was theoretically analyzed taking variations of the boiling point elevation (BPE) into account. The still consists of a series of seawater-soaked wicks stuck on closely-spaced parallel plates with the first plate steam-heated at 100°C and the last plate cooled in 30°C ambient air. Evaporation from the wicks increases the BPE more rapidly at downstream distances closer to exits of evaporating areas, and this increase reduces evaporation flux significantly at downstream regions on the wicks. An 80% heat recovery from products of hot condensate and concentrate reduces the steam consumption by 46%. The steam consumption decreases more rapidly with an increasing number of wicks than does the production rate; thus, a lower steam consumption ratio is observed for the still having more wicks. Narrowing the gaps between the plates greatly increases the production rate with a slight decrease in the steam consumption ratio. The still with 19 wicks with 1 m by 2 m evaporating areas, 5 mm gaps and 80% heat recovery produces 12 kg distillate and 3.3 kg concentrate of 0.16 kg/kg-water concentration per 1 kg steam consumption with a 26.4 kg/h distillate production rate.     

Oxygen evolution anodes composed of anodically deposited Mn-Mo-Fe oxides for seawater electrolysis

Preparation of anodes for oxygen evolution in seawater electrolysis was carried out. Manganese-molybdenum double oxides, Mn_1−xMo_xO_2+x, prepared by anodic deposition from MnSO₄-Na₂MoO₄ solutions showed the 100% oxygen evolution efficiency at a current density of 1000 A m⁻² in 0.5 M NaCl at 30 °C and pH 12, but an increase in solution temperature resulted in dissolution of the oxides as molybdate and permanganate ions. In order to increase the stability of the electrodes at higher temperatures the addition of iron to the manganese-molybdenum oxides was performed by anodic deposition in MnSO₄-Na₂MoO₄-FeNH₄(SO₄)₂ solutions. The electrodes thus prepared showed the 100% oxygen evolution efficiency at 1000 A m⁻² in 0.5 M NaCl at 30-90 °C, when proper amounts of molybdenum and iron were contained. The iron addition also enhanced the oxygen evolution efficiency. The electrodes were not composed of oxide mixtures but triple oxides, Mn_1−x−yMo_xFe_yO_2+x−0.5y, consisting of Mn⁴⁺, Mo⁶⁺ and Fe³⁺. The formation of the triple oxides seemed responsible for enhancement of both oxygen evolution efficiency and stability.     

沿海电厂露天布置循环水泵出口液控蝶阀的可靠性优化

循环水泵出口液控蝶阀关系到循环水泵自身乃至整台机组的安全运行。但露天布置的液控蝶阀跟传统室内布置的液控蝶阀比,其运行环境比较恶劣,对系统的安全投运带来许多隐患。针对浙江大唐乌沙山发电厂出现的问题,本文从热控角度提出选型、安装、维护等方面的几点建议。     

Materials for global carbon dioxide recycling

CO₂ emissions, which induce global warming, increase with the development of economic activity. It is impossible to decrease the CO₂ emissions by suppression of the economic activity. Global CO₂ recycling can solve this problem. The global CO₂ recycling consists of three district: The electricity is generated by solar cells on deserts. At desert coasts, the electricity is used for H₂ production by seawater electrolysis and H₂ is used for CH₄ production by the reaction with CO₂. CH₄ which is the main component of liquefied natural gas is liquefied and transported to energy consuming districts where CO₂ is recovered, liquefied and transported to the desert coasts. A CO₂ recycling plant for substantiation of our idea has been built on the roof of the Institute for Materials Research in 1996. Key materials necessary for the global CO₂ recycling are the anode and cathode for seawater electrolysis and the catalyst for CO₂ conversion. All of them have been tailored by us. They have very high activity and selectivity for necessary reactions in addition to excellent durability. A pilot plant consisting of minimum units in an industrial scale is going to be built in three years.     

铝合金在海洋环境中的腐蚀研究(Ⅲ)--海水飞溅区16年暴露试验总结

获得了10种铝合金在青岛海域海水飞溅区暴露16年的腐蚀结果，总结了它们在飞溅区的腐蚀行为和规律。在飞溅区，铝合金对点蚀、缝隙腐蚀较敏感。L4M在飞溅区的耐点蚀性能较差。LF2Y2、LF3M的耐点蚀性能好于L4M。在10种铝合金中LD2CS的耐点蚀性能最好。180YS、LF21M除点蚀、缝隙腐蚀外还发生层间腐蚀。LY11CZ（BL）、LY12CZ（BL）和LC4CS（BL）的包铝层起着牺牲阳极的作用，基体受到有效保护。铝合金在飞溅区的缝隙腐蚀比点蚀严重。在海水飞溅区暴露的铝合金，开始4年的点蚀速度较快，4年后点蚀速度随时间逐渐减慢。暴露8－16年，铝合金的点蚀深度没有明显加深。     

直控电反馈式微流量海水比例压力阀及其应用系统研究

针对海水介质的特点，研制了一种直控电反馈式微小流量海水比例压力阀，对其进行了理论分析。将该阀应用在深海极端环境模拟系统中，并进行了实验研究。结果表明：该阀的调压范围、调压精度均满足设计要求，并具有较好的静、动态特性。     

紫铜海水管焊接接头部位的腐蚀研究

紫铜海水管系经常在焊接接头部位发生腐蚀穿孔泄漏,分析主要是由于结构不均匀性和成分不均匀性所致。实验研究表明,用黄铜焊条所形成的焊缝组织为α β相,在海水中极易发生脱锌腐蚀,白铜焊条因镍的存在所形成的焊缝组织仍为铜-镍-锌三元单相固溶体(α相),因而具有较好的耐海水腐蚀性能。